This is a resubmission of a competing renewal for a highly successful training program in transplantation immunology and stem cell biology. Over the past 11 years, a dynamic group of internationally recognized investigators in transplantation and stem cell biology were strategically recruited to the University of Louisville which is increasingly recognized for its comprehensive translational research in composite tissue allotransplantation, tolerance, and stem cell-mediated regenerative medicine. This training program directly addresses the mission of the NIH training grant program to help ensure that a diverse and highly trained workforce is available to assume leadership roles related to the nation's biomedical research agenda. All positions have been filled with outstanding applicants to date including six women (one minority), thereby addressing the major concern of all three reviewers. Applicants must have a Ph.D., D.V.M., or M.D. They are required to submit a CV, publication list, three letters of recommendation, and a statement of the specific research proposed. An Executive Training Committee comprised of the program Director and senior trainers selects the trainees. Trainees assemble a program and undertake basic research with one trainer and one or more co-mentors. Evaluation of the Training Program occurs on several levels, including manuscript and abstract submissions; oral presentations and participation at research seminar series; and completion and submission of an NRSA postdoctoral individual training grant or equivalent (AHA, JDRF, ASH, or other foundation or society fellowships) within the second year of training. The overall progress of this Training Program is assessed by an External Advisory Board through semiannual meetings and feedback. The External Advisory Board also assists in minority recruitment. The faculty in this training program has the expertise and breadth of background to successfully train fellows in well-equipped, centrally-located laboratories, it is our goal that our trainees will be qualified to assume leadership positions related to transplantation and stem cell biology in industry, academia, and biotechnology. Our established track record demonstrates that we are well on our way to achieving this goal.